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Module containing various utils used throughout Hyperdrive.

There is a newer version: 0.1.159

package org.brightify.hyperdrive.utils

import kotlinx.coroutines.FlowPreview
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.emptyFlow
import kotlinx.coroutines.flow.flatMapConcat
import kotlinx.coroutines.flow.flowOf

public sealed interface Optional {
    public data class Some(public val value: T): Optional

    public object None: Optional

    public fun withValue(block: (T) -> Unit) {
        if (this is Some) {
            block(value)
        }
    }
}

public inline fun  Optional.toKotlin(): T? {
    return when (this) {
        is Optional.Some -> value
        is Optional.None -> null
    }
}

public inline fun  T?.toOptional(): Optional {
    return this?.let { Optional.Some(it) } ?: Optional.None
}

public inline fun  Optional.map(transform: (T) -> U): Optional {
    return flatMap { Optional.Some(transform(it)) }
}

public inline fun  Optional.mapToKotlin(transform: (T) -> U): U? {
    return when (this) {
        is Optional.Some -> transform(value)
        is Optional.None -> null
    }
}

public inline fun  Optional.flatMap(transform: (T) -> Optional): Optional {
    return when (this) {
        is Optional.Some -> transform(value)
        is Optional.None -> Optional.None
    }
}

@OptIn(FlowPreview::class)
public fun  Flow>.filterSome(): Flow {
    return flatMapConcat {
        when (it) {
            is Optional.Some -> flowOf(it.value)
            Optional.None -> emptyFlow()
        }
    }
}

public inline fun  Optional.someOrDefault(block: () -> T): T {
    return when (this) {
        is Optional.Some -> value
        Optional.None -> block()
    }
}